Filling in a 20mm hole that's too big for sealant

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neb

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#230588 3-Mar-2018 10:38

I've got a 20-22mm hole under the eaves of the house with a 12mm alu bar (that containg wiring) coming out of it:

and I'm looking at ways of sealing it up. Standard acrylic sealant won't do it because of the size of the gap, so I'm thinking of...

1. Gorilla foam with sealant over the top.

2. Put a 16mm alu channel over the top of it, which will fill the 20mm hole to a level where I can use acrylic sealant.

3. Cut a 20mm dowel in half to form a plug, and seal up the remaining gap.

Any thoughts on that, or any other ideas? None are perfect, but I'm sorta leaning towards the gorilla foam at the moment, although it's horrible stuff to remove if I ever need to replace anything.

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#1967462 3-Mar-2018 11:16

Why not just bog it up?

Richard rich.ms

cruxis

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#1967463 3-Mar-2018 11:21

Yep Builders Bog and paint.

https://www.bunnings.co.nz/turbo-builder-s-bog-500ml_p00712784

frankv

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#1967467 3-Mar-2018 11:26

I'd 3D-print a neat cover for the whole thing, and screw/glue it in place.

FineWine

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#1967468 3-Mar-2018 11:31

cruxis:

Yep Builders Bog and paint.

https://www.bunnings.co.nz/turbo-builder-s-bog-500ml_p00712784

Put a balled up bit of chicken wire in the hole then use the Builders Bog or crunched up newspaper and Builders Bog. I've done both before especially on bigger holes.

Whilst the difficult we can do immediately, the impossible takes a bit longer. However, miracles you will have to wait for.

nunz

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#1967494 3-Mar-2018 12:27

Make a template that is slightly wider than the hole out of cardboard, timber etc.
Drill a screw into the middle of the template
Cover the surface of the template with adhesive (ados, gorilla grip, builders nails.
Insert it into the hole - the screw lets you keep hold of it.
Pull it towards you and the adhesive will stick it against the inside of the hole.
LEt it dry and remove the screw.
Then bog / putty / plaster over the top of that.

Using a template will give you a much better base than just filling the hole with bog - it gives a foundation to put your filler onto.

A template could be two sticks of wood - one above the conduit and one below then cross hatch a couple of other bits of wood on top. Chicken wire etc is good but a big hole presents problems if the filler has no base to sit on.

Gorrilla or sellys expanding foam is another option. Pump it in and let her expand to fill the whole. However the same issue applies - what does it hang onto. Once dry it can be sanded flat / into shape.

Good article on different filler types here. Pros and cons. -> https://www.hunker.com/13401515/the-best-wood-filler-for-large-holes

The really correct artisan way:

Enlarge the hole - square it up.
Cut a piece of wood to fit the newly enlarged hole.
Put wings on two sides of the back of the wood plug
Put adhesive onto the fronts of the wings
Insert into hole and pull it forward to the wings connect firmly inside the hole. (a screw in the centre of the plug helps pull it forward)
Paint and putty over the minor cracks left.

nunz

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#1967497 3-Mar-2018 12:33

FineWine:

cruxis:

Yep Builders Bog and paint.

https://www.bunnings.co.nz/turbo-builder-s-bog-500ml_p00712784

Put a balled up bit of chicken wire in the hole then use the Builders Bog or crunched up newspaper and Builders Bog. I've done both before especially on bigger holes.

Looking at your signature - tag line. Are you an agent provocateur for France? After France bombed the rainbow warrior I am surprised they can take a moral stance on green issues :) The temptation to fill in the form as coming from Syria or similar was really tempting.

</humour>

Wish NZ would step up their game in this regard.

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Mike61

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#1967582 3-Mar-2018 17:10

Why not just use some MS sealant? I've done 40mm holes with it before. It sticks like sh**.

neb

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#1967621 3-Mar-2018 19:08

nunz:
Make a template ...

Ah, that's the missing magic! I'd mentally crossed out bogging it up because the filler I've worked with in the past (one-component, admittedly, I'm lazy :-) warns about applying it more than a few mm at a time due to curing/cracking issues, so packing it full of bog seemed a non-starter. By putting in a template as backing, I can use filler to deal with the problem.

Mavarick

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#1968193 5-Mar-2018 10:38

Would that bog work on Linna board too? took out the bulkhead lights and replaced with down lights in the soffit and need something that wont expand or contract. thanks

wellygary

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#1968232 5-Mar-2018 11:49

oh for gawds sakes its 20mm, its the size of a $1 coin,

Use expanding foam, (gorilla filler is perfect) then cut it back, seal and paint,

neb

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#1968244 5-Mar-2018 12:41

Mavarick:
Would that bog work on Linna board too? took out the bulkhead lights and replaced with down lights in the soffit and need something that wont expand or contract. thanks

Could you post a photo of what you need to fill? If you need to fill a hole you've drilled for the power cable that's one thing, but packing bog around a light or light fitting isn't a good idea...

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Mavarick

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#1968252 5-Mar-2018 12:52

neb:
Mavarick:

Would that bog work on Linna board too? took out the bulkhead lights and replaced with down lights in the soffit and need something that wont expand or contract. thanks
Could you post a photo of what you need to fill? If you need to fill a hole you've drilled for the power cable that's one thing, but packing bog around a light or light fitting isn't a good idea...

I'll get a photo up later, the cable has been removed from the wall , no longer any fitting or wires there, I did call the Hardies helpline, but if its over the size of the nail or screw hole they dont recommend anything, there way of getting out of any water issuses I suppose.

Mavarick

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#1968518 5-Mar-2018 21:25

neb

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#1970144 6-Mar-2018 20:21

wellygary:
oh for gawds sakes its 20mm, its the size of a $1 coin,

The reason I'm asking is that in other posts I've complained endlessly about the cowboy work done on this place by previous owners (latest gem: Was working under the eaves and looked down at the flashing over the kitchen window, they'd packed freakin' polyfilla (or at least one of the chalk/gypsum fillers) into the gap between the top of the fibrolite and the flashing, which was now a crumbling line of flaky, chalky gunk with a mm or two of gap on each side). So before I end up as the next owner's cowboy, I wanted to get advice on how to do it properly. The template trick worked fine.

neb

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#1970148 6-Mar-2018 20:27

Mavarick:

That's pretty tiny, I'd use an acrylic-based filler, Bunnings has one for just under $4 so you don't feel so bad about throwing away 90% of the tube when it hardens. It's sandable, paintable (unlike a lot of silicone sealers), and pretty durable, I've been using it to stop up various gaps in exterior walls.

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